塔里木河下游不同覆盖度灌木防风固沙功能野外观测研究

 对塔里木河下游50%、25%、10%三种覆盖度灌木降低风速观测结果表明: 50%覆盖度灌木降低风速最明显，防风效能为49.21%；25%的覆盖度灌木降低风速较明显，防风效能为24.44%;10%的覆盖度灌木对风速降低有一定作用，防风效能为9.15%。在7.7 m.s-1风速下，植被覆盖度为10%、25%的沙地输沙率分别是无植被覆盖沙地的62.44%和8.37%；在10 m.s-1风速下，植被覆盖度50%的沙地仅有轻微的风蚀。根据塔里木河下游不同覆盖度植被与降低风速之间的定量关系，得出不同风速条件下的有效植被覆盖率，在研究区常见10～15 m.s-1风速条件下，要达到有效阻沙效果，植被覆盖率应在50%以上。

Field Investigation on Function of Reducing Wind and Stabilizing Sand under Different Vegetation Cover in Lower Reaches of Tarim River

Investigation into the effect on reducing wind under three kinds of different vegetation coverage(50%,25%,10%) in lower reaches of the Tarim River shows that their effect are respectively 49.21%, 24.44% and 9.15%. Under wind velocity of 7.7 m\5s-1, the sand transporting rate over vegetation coverage of 10% and 25% is respectively 64.44% and 8.37% of that over non-vegetation cover; Under wind velocity of 10 m\5s-1, only slight wind erosion occurred on the land with 50% vegetation coverage. Quantitatively analysis on the relationship between different vegetation coverage and reduction of wind velocity shows the effective vegetation degree of coverage. Under the common wind velocity (10~15 m\5s-1), the effective vegetation coverage should be above 50% for preventing wind erosion.